<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div style="position: relative;z-index: auto">
    <img src="1.jpg" style="position: absolute;z-index: 1"/>
</div>
<div style="position: relative;z-index: auto">
    <img src="2.jpg" style="position: absolute;z-index: 1"/>
</div>
</body>
</html>